Water- indicatoes foe steam-geeeeatoes



@uiten tatea atrat l @ffice Letters .Patent No. 76,893, dated April 21,1868

IMPROVEMENT IN LOW-WATERINDICTORS FOR STEAM-GENERATORS.

titte dpmli nehmt tu in tipa tttarlneut uitbarsting ritt nf 11p same.

TO ALL WHOM ITMAY CONCERN: p

Be it known that I, LEvI H. COLBORN, of Chicago, in the county of Cook, and State of Illinois, have invented a. new and useful Improvement in Low-Water Indicators for Steam-Boilers; and I dohereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and the letters and figures marked thereon, which form a part of this specification.

The nature of myinvention consists in arranging within a chamber or vessel communicating with the boiler at low-water mark, a Heat-valve seating outwardly against a seat composed of a metal which will expand from heat more than the valve itself, so that as the water rises above the low-water' mark, it will lo'at and seat the valve, and prevent the escape of water or steam through the valve, but when the water falls below low-water mark, and thereby uncovers the communication of the chamber with the boiler, steam will be admitted to the chamber, and by heating the scat of the valve and expanding same, allow a leakage of steam through the valve, and so destroy the excessof pressure upon the inside of the valve, and allow the same to open and give a free escape to the steam, the escaping steam being employed either to sound an alarm, operate a feed-pump, or regulate a valve in a feed-water pipe. In the accompanyingdrawing Figure I is a sectional elevation of my improved device, and a boiler vto which it is connected.

Figure II is a plan view of the same.

Like letters refer to like parts in each of the figures.

A represents the boiler, of any-common and well-known construction. g

B represents the valve-chamber or vessel, open at the top, and located at one side of the boiler, and connects ing therewith by. a pipe, C, which opens into the boiler at low-water line, so that its bore will be covered by the water when it is above low-water line, and uncovered when it is below low-water line.

D represents the valve, which is made to float by being made hollow, or by being connected with a float of 4 wood, or by any other convenient mode of construction, said valve being guided in its movement by the crossarms D. The valve-seat is formed at the upper side of the chamber B, either in the same casting which forms the chamber, or in a separate casting connected therewith. The valve seats outwardly, and covers the opening through the top of the chamber, so that when seated it prevents the escape of water or steam from the chamber. The entire casing whichforms the chamber, when the valve-seat is cast therewith, should be made of a metal possessing greater capacity for expansion by heat than the metal used for the valve its'elf, as, for instance, brass for the casing and iron for thevvalve.

When the valve-sentis made separate fr'om the' casing, it will be sufficient to make it of brass, while the casing may bc made of iron. A pipe, E, leads from the open top of lthe chamber to 'either a pony-engine or boiler-feed pump, or an alarm-whistle, or both, located in any convenient position.

When a. full supply of water is in the boiler, it will fill the chamber I3 and iioat the valve D into its seat. and so retain the same until the water falls to low-water mark, and thereby uncovers the pipe C and allows the steam from the boiler to pass into and lill the chamber. The pressure of the steam will still retain the valve against its seat until the seat becomes heated, and' thereby expanded sufficiently to permit a leakage of steam past the same, which leakage, as soon as it takes place, will relievethe outward pressure upon the valve, and

cause the same to fall by its own weight,land fully open the passage to the pipe E. Inorder to prevent the pressure upon the valve from forcing it upward as its seat-expands, which would have the ell'ect to prevent thc required leakage, a shoulder, f, is formed in the valve-seat, against which the valve will bear, though notsteamtight, which bearing of the valvewill not be affected by the expansion of the valve seat, A shoulder on the valve would accomplish the same/result.

When the valve opens as above described, the steam will ow'from the boiler, and, passing through the pipe E, operate any suitable mechanism, as a feed-pump, or the regulating-valve of a feed-pump, and admit an additional supply of water into .the boiler until the valve shall be again floated to its seat, when the supply and consequently the feed, until the con` of steam being shut o, the action of such mechanism will cease,

hen the above-described operation will be' sumption of wntci by the boiler shall require an additional supply, w repented.

What I clnimi'a-s my invention, is Y A low-water indicator for steam-boilers, constructed, connected, and operating substantially as herein described. l

LEVI COLBORN.

Witnesses:

LEWIS L. COBURN, W. E. Minus. 

